Work machines, such as skid steer loaders, multi terrain loaders, backhoe loaders, agricultural tractors, track-type tractors, articulated trucks, wheel loaders, and other types of construction, mining, or agricultural machinery are used for a variety of tasks requiring operator control. Typically, an operator controls these machines through an interface. Due to the jostling of the machine as it travels over rough terrain and the long hours that an operator can expect to remain in the machine, operator compartments typically have adjustable operator interfaces. These operator interfaces have adjusting mechanisms that include ergonomically adjustable seats, armrests, and control levers.
For skid steer loaders, multi terrain loaders, and other compact work machines, the operator compartment may include rollover protection, falling-object protection, and seat belts. These components result in a compact seating area with limited access through the front of the machine. Adjusting mechanisms that allow for ergonomic positioning of the operator interface may hamper entry and exit from the operator compartment.
One example of an adjustable operator interface that attempts to address this is disclosed in U.S. Patent Application No. 2002/0145325 to Clevenger (“Clevenger”). Clevenger discloses an armrest structure for a skid steer loader. The operator compartment or cab includes two control levers that are fixed to the floor. A seat, mounted along slides, may move fore and aft parallel to the direction of vehicle travel. Left and right armrests are pivotally attached to the cab walls. The armrests may be rotated upward transverse to a direction of vehicle travel as an operator enters and exits. The armrests may be adjusted up or down to one of three vertical positions.
While the operator interface in Clevenger is adjustable, the control levers are not. For pilot controlled hydraulics, this is a typical arrangement. In such cases, due to the hydraulic lines that extend from the hydraulic system to the controls, the control levers are typically fixed with respect to the cab floor. As a result, the seat must be adjusted relative to the control levers, typically requiring an operator to awkwardly reach for the bottom of the seat and engage a slide mechanism. The fixed control levers also may hamper entry and exit from the operator compartment.
Operator interfaces having moveable control levers have been disclosed. For example, U.S. Pat. No. 4,702,520 to Whisler (“Whisler”) discloses an adjustable armrest with integral vehicle controls. However, Whisler requires that an operator awkwardly reach to the sides and rear of the armrests to make any adjustments. Further, Whisler lacks an armbar that wraps around the seated operator.
The present invention is directed to overcome one or more of the problems as set forth above.